Emphasis is being placed upon identification of phytopathogenic microorganisms that can serve as sources of enzymes that degrade the various polysaccharide constituents in the plant cell wall. Also, procedures are being developed for purification of the following enzymes: Alpha-1,4 endopolygalacturonase, alpha-1,4 exopolygalacturonase, alpha-1,4 endopolygalacturonate lyase, beta-1,4 endoxylanase, alpha-1,5 and alpha-1,3 arabinanases, beta-1,4 glucanase (cellulase), and beta-1,4 galactonase. The above enzymes can be obtained from the following pathogens: Sclerotium rolfsii, Fusarium roseum Avenaceum, Erwinia chrysanthemi and Rhizoctonia solani. Procedures have been developed for purification of several alpha-1,4 endopolygalacturonate lyase isoenzymes. Difficulty has been experienced in preparing the other enzymes in homogeneous form to date. Two approaches are now being taken to solve this problem: 1) specific induction of a given enzyme in the source organisms and 2) development of affinity column chromatography for purification of beta- 1,4 galactanases, endopoly galacturonases and cellulases. Some progress has been achieved in in both areas. This project should yield sources of enzymes useful in studying structural aspects of polysaccharides.